Zigzag attachment for a two needle sewing machine



R. J. BOSER 7 Nov. 29, 1966 ZIGZAG ATTACHMENT FOR A TWO NEEDLE SEWING MACHINE Filed Sept. 2., 1964 5 Sheets-Sheet 1 mm m MJJYA M 0 RY B Nov; 29, 1966 R. J. BOSER 3,288,092

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ZIGZAG ATTACHMENT FOR A TWO NEEQLE SEWING MACHINE 5 Sheets-Sheet 4 Filed Sept. 2, 1964 76 77 INVENTOR 1966 R. J. BOSER 3,238,092

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United States Patent 3,288,092 ZIGZAG ATTACHMENT FOR A TWO NEEDLE SEWING MACHINE Ronald J. Boser, 261-79 Langston Ave., Glen Oaks, N.Y. Filed Sept. 2, 1964, Ser. No. 394,017 Claims. (Cl. 112-100) This invention relates generally to sewing machine attachments. More specifically it relates to attachments for sewing zigzag stitches.

It is generally Well known to those skilled in the art that it has not been possible heretofore to attach the edges of two materials in abutment position to each other by a zigzag ornamental thread across the seam formed by the edges without the possibility of the seam becoming permanently widened when the materials are stressed apart.

Accordingly it is a principal object of the present invention to provide a zigzag attachment having self contained means whereby the seam formed by the edges of two materials in abutment with each other will not stretch or widen when the materials are secured together by a zigzag stitch.

Another object of the present invention is to provide a zigzag attachment having means to produce a zigzag thread which is utilitarian and wherein the decorativeness of a zigzag thread is only secondary. It is further of course well known that decorativeness has been a principal object heretofore in zigzag threads.

It is still another object of the invention to provide a zigzag attachment which is designed for use upon conventional lockstitch sewing machines having two needles.

It is yet another object of the invention to provide a zigzag attachment which produces a zigzag thread which is in combination with a lock thread.

It is a further object of the invention to provide a zigzag attachment which produces a zigzag thread adjacent one exposed side of material being enjoined.

Still other objects are to provide a zigzag attachment for two needle sewing machines which is of relatively simple design, inexpensive to manufacture, rugged in construction, easy to use, and efficient in operation.

These and other objects will be readfly apparent upon a study of the following specification and the accompanying drawings wherein:

FIGURE 1 is a perspective View of a sewing machine head shown fragmentarily and showing the present invention incorporated therewith,

FIG. 2 is a top plan view of a looper element which forms a principal part of the present invention,

FIG. 3 is a side elevational view thereof,

FIG. 4 is a perspective view of a sewing machine head shown fragmentarily and showing the invention incorporated therewith and in operative use,

FIG. 5 is a bottom plan view of the sewing machine head,

FIG. 6 is a cross sectional view through line 66 of FIG. 5 shown looking into the direction of the arrows thereof,

FIG. 7 is a cross sectional view through line 7--7 of FIG. 5 shown looking into the direction of the arrows thereof,

FIG. 8 is a cross sectional view through line 8-8 of FIG. 4 shown looking in the direction of the arrows thereof,

FIG. 9 is a cross sectional view through line 99 of FIG. 8 shown looking in the direction of the arrows thereof,

FIG. 10 is a cross sectional view of a tape formation formed by the present invention,

3,288,092 Patented Nov. 29, 1966 ice FIG. 11 is a cross sectional view of a further modified seam formed by the present invention,

FIG. 12 is a cross sectional view of a still further modified seam formed by the invention,

FIG. 13 is a cross sectional view of yet another modified seam formed by the present invention,

FIG. 14 is a cross sectional view similar to FIG. 8 showing a modified application of the invention,

FIG. 15 is a cross sectional view through line 15-15 of FIG. 14 shown looking into the direction of the arrows thereof,

FIG. 16 is a bottom view thereof, and

FIG; 17 is a bottom view showing a modified zigzag thread.

Referring now to the drawing in detail, the numeral 10 represents a zigzag attachment for two needle sewing machines according to the present invention which is incorporated in a conventional sewing machine. The machine includes a base 12 that carries hook mechanism therewithin. An arm 13 extends upwardly from the base and carries the needle bar mechanism 14 which in the present case includes a single needle bar 15 carrying a pair of needles 16 in tandem. The arm also supports a presser foot bar 17 at the rear of the needle bar, presser foot bar carrying at its lower end a presser foot 18. The presser foot incorporates an upper folder unit 19 therewith which serves to fold tape 29 received unfolded from a reel above (not shown) and then delivers the folded tape 20a under the presser foot and over a material being sewn. Upon the upper side 21 of the base 12 there is located near the front edge 22 thereof a looper unit 23 and a lower folder unit 24.

The looper unit includes a looper arm 25 of generally longitudinal character that is mounted near one end 26 about a pivotable shaft 27. The arm has an opening 28 within which shaft 27 is received, and the end 26 is bifurcated by means of open slot 29 which extends from the end edge 30 to the opening 28. A screw 31 extends transversely through the bifurcated end, passing through a clearance opening 32 in one of the fork elements thereby permitting adjustment and securement of the looper arm on the shaft. At the opposite end 34 of the looper arm there is mounted a relatively thin tube 35 having a central opening 36, the tube extending rearwardly from the looper arm to a point relatively close to the forward edge of throat plate 37 and the openings 38 therein. The end 34 of the looper arm is also bifurcated in similar manner by a slot 39, and the fork elements thereof are likewise forced together by means of a screw 40 thereby clamping the fork elements around the tube and securing the same to the looper arm.

A stationary tube 41 is mounted along the forward edge 22 of the base and thread 42 from a spool (not shown) is drawn through the tube 41 and then through the tube 35 to the needle vicinity where it can co-operate with threads 43 of the two needles to produce the novel ornamental thread of this invention which shall be described later below.

It is to be noted that the looper unit is spaced apart from the upper side 21 of the base, and the lower folder unit 24 extends into this space under the looper arm, as is shown in FIGS. 1, 8 and 14 of the drawings. Unfolded tape 44 from a reel (not shown) is drawn into the opening at the forward end of the folder unit 24 and it then is withdrawn from the rear end thereof in folded condition as shown at 44a. The rear end of folder unit 24 is located relatively close to the forward edge of the throat plate and needle openings 38, similarly as the rear end of tube 35. Thus the folded tape 44a passes directly over and adjacent the throat plate during sewing operation.

A pair of rails 45 are mounted by means of screws 46 on the upper side 21 of base 12, the looper unit and lower folder unit being located therebetween. An angular groove 47 is provided in each rail, and a cover plate 48 has opposite side edges 49 which are slidable in the grooves, thus providing a closure for the looper and lower folder units. A pair of screws 50 pass through the cover plate, the screws being secured in threaded openings 51 in the rails, thus securing the cover in place. The rear edge 52 of the cover plate restsadjacent' the forward edge of the throat plate, thereby enclosing the tube. On the upper side of the cover plate there is an upstanding divider plate 53 which serves as a lateral guide for the edges 54 of materials 55 and 56 being enjoined by sewing upon the machine. A modified cover plate (not shown) having no divider plate is used on work wherein a zigzag ornamental thread is desired on a singular piece of material (as shown in FIG. 10).

The shaft 27 extends through the base 12 to the underside thereof as is shown in FIGS. and 6. The lower end of the shaft is secured to one end of a lever '57; the opposite end of the lever being attached pivotally free by means of a' pin 58 to one end of a push rod 59; the opposite end of which is attached pivotally free by means of pin 59 to a bar 60 adjustably mounted on a rotating cam plate 61. The bar 60 is provided with slots 62, and screws 63.extend therethrough, the screws being secured in threaded openings on the cam plate. Thus adjustability of cam throw is obtainable. The cam plate is affixed on shaft 64 which is mounted rotatably free in a bracket 65 secured to the underside 66 of the base. A gear 67 mounted rigidly on shaft 64 is driven by a gear 68 mounted on the base main shaft 69. The base main shaft is powered by a belt 70, passing around pulley 71 mounted on main shaft 69 and the belt also passing around pulley 72 mounted on arm main shaft 73. The arm main shaft is driven by means of a motor driven belt 74 passing around pulley '75.

In operative use, materials 55 and 56 to be enjoined are fed under the presser foot in edge abutment with each other, the edge of each being adjacent one side of the divider plate 53. At the same time the upper tape 20a feeds onto the upper sides of the enjoining materials, one half of the tape being over the upper side of each enjoining material. the underside of the enjoining materials, one half of the tape being under the lower side of each enjoining material. with a thread 43 produce together with threads 43a from bobbinstnot shown) within the base a resultant two rows of lock threads 76 and 77.

At the same time, the looper arm 25 pivots or zigzags back and forth, as shown in FIG. 5; the rear edge of tube 35 slightly over-riding laterally the line of the lock thread. Thus upon each formation of a lock thread the looper arm tube causes thread 42 to pass around one of the rows of threads 76 and 77. Thus the resultant threads shown in FIG. 9 is formed wherein the zigzag threads pass around the lock threads.

In FIG. 10, a singular material 78 is used with tapes 20a and 44a instead of two materials in abutment. As shown in FIGS. 11 to 13, modified types of seams can be produced. In FIG. 11, materials 79 and 80 are attached in spaced apart relation without benefit of tapes. Additionally, the materials are folded in folders prior to threading. In FIG. 12, a similar seam is produced by use of four materials 81, 82, 83 and 84. In FIG. 13,

.the edge of one material 85 overlies the edge of another enjoining material 86.

In FIG, 14, a seam is produced wherein only the upper tape is dispensed for attachment to materials 55 and 56; the lower tape being not used. In such case the zigzag thread is visible on the underside as shown in FIG 16.

In FIG. 17, the timing of zigzag motion of tube 35 is altered to double speed thereby producing the seam shown.

While various changes may be made in the detailed construction, it shall be understood that such changes shall At the same time the lower tape 44a feeds on I During stitching operation the two needles each fined by the appended claims.

Having thus set forth my invention, what I claim as new and desire to secure by Letters Patent of the United States 1. In a two needle sewing machine having a base, an overhanging arm and a main drive shaft mounted on said base, the combination of a zigzag attachment having a looper mechanism comprising a looper drive mechanism and a looper zigzag mechanism, said looper drive mechanism driving said looper zigzag mechanism, said looper zigzag mechanism adapted to carry a thread being dispensed from said looper zigzag mechanism to cooperate with a lock thread formed by each of said needles to form a zigzag thread, said looper drive mechanism comprising a gear, said gear being mounted on said main drive shaft base, said gear being driven by said main shaft, a second gear, said second gear being driven by thefirst said gear,

a second gear shaft carrying said second gear, a cam mounted on said cam plate, a plurality of elongated slots on said sliding bar, a plurality of screws mounted on said cam plate, said screws having each an enlarged head said screws passing through said slots of said sliding bar, said screw heads overlapping the edge of said slots for clamping againt said sliding bar, said sliding bar being radially movable relative to an axis of said second gear shaft, a pushrod, one end of said push rod being freely pivoted to a longitudinal midpoint of said sliding bar, a lever, a looper zigzag mechanism shaft, the opposite end of said push rod being freely pivoted to one end of said lever, and the opposite end of said lever being rigidly affixed to one end of said looper zi zag mechanism shaft, a looper arm, one end of said looper arm being rigidly afiixed to the opposite end of said looper zigzag mechanism shaft, a looper tube, the opposite end of said looper arm carrying said looper tube, an opening extending through said looper tube, said looper tube having one end extending relatively close to said two needles of said sewing machine, said looper drive mechanism being on the underside of said sewing machine base, and said looper zigzag mechanism being on the upper side of said sewing machine base, said looper zigzag mechanism shaft extending through said base from a lower to an upper side, a pair of rails mounted on said base, an angular. groove in each of said rails, a cover plate, said cover plate having opposite parallel edges, said parallel edges being slidably received within said grooves of said rails and said cover plate enclosing with said slot therein, said looper tube received in said,

second opening, and a second transverse screw connect-. ing said second bifurcated ends to clamp said looper tube in said second end.

3. In a two needle sewing machine the combination as i set forth in claim 2 wherein there is a lower folder unit for tape, said lower folder unit comprising a generally horizontal element located below said looper arm, said horizontal element dispensing folded tape below the exit end of said looper tube and thereby below the thread being dispensed from said looper zigzag mechanism.

4. In a two needle sewing machine the combination as set forth in claim 3, including a transversely extending tube mounted along the front edge of said sewing machine base, one end of said transverse tube being located relatively close to said end of said looper arm tube which is clamped in said looper arm, the opposite end of said trans- References Cited by the Examiner verse tube adapted to receive thread from a spool source whereby said thread is guided through said transverse UNITED STATES PATENTS tube and through said looper arm tube to a position ad- 10,597 3/1854 Johnson 112-497 jacent said two needles of said sewing machine. 5 541,479 6/1895 Fefel 112100 5. In a two needle sewing machine the combination as 946,150 1/1910 Parkes 112100 X set forth in claim 4 including an upstanding divider plate 2,067,340 1/1937 azak 112100 on the upper side of said cover plate, said divider plate 2,534,701 12/1950 Dlamond 11210O being in longitudinal alignment with an imaginary line passing midway between said two needles in the direction 10 JORDAN FRANKLIN Pr'mary Exammer of feed. A. R. GUEST, Assistant Examiner. 

1. IN A TWO NEEDLE SEWING MACHINE HAVING A BASE, AN OVERHANGING ARM AND A MAIN DRIVE SHAFT MOUNTED ON SAID BASE, THE COMBINATION OF A ZIGZAG ATTACHMENT HAVING A LOOPER MECHANISM COMPRISING A LOOPER DRIVE MECHANISM AND A LOOPER ZIGZAG MECHANISM, SAID LOOPER DRIVE MECHANISM DRIVING SAID LOOPER ZIGZAG MECHAISM, SAID LOOPER ZIGZAG MECHANISM ADAPTED TO CARRY A THREAD BEING DISPENSED FROM SAID LOOPER ZIGZAG MECHANISM TO COOPERATE WITH A LOCK THREAD FORMED BY EACH OF SAID NEELDLES TO FORM A ZIGZAG THREAD, SAID LOOPER DEIVE MECHANISM COMPRISING A GEAR, SAID GEAR BEING DRIVEN BY SAID MAIN SHAFT, A SECOND BASE, SAID GEAR BEING DRIVEN BY SAID MAIN SHAFT, A SECOND GEAR, SAID SECOND GEAR BEING DRIVEN BY THE FIRST SAID GEAR, A SECOND GEAR SHAFT CARRYING SAID SECOND GEAR, A CAM PLATE MOUNTED ON SAID SECOND GEAR SHAFT, A SLIDING BAR MOUNTED ON SAID CAM PLATE, A PLURALITY OF ELONGATED SLOTS ON SAID SLIDING BAR, A PLURALITY OF SCREWS MOUNTED ON SAID CAM PLATE, SAID SCREWS HAVING EACH AN ENLARGED HEAD, SAID SCREWS PASSING THROUGH SAID SLOTS OF SAID SLIDING FOR CLAMPSCREW HEADS OVERLAPPING THE EDGE OF SAID SLOTS FOR CLAMPING AGAINST SAID SLIDING BAR, SAID SLIDING BAR BEING RADIALLY MOVABLE RELATIVE TO AN AXIS OF SAID SECOND GEAR SHAFT, A PUSH ROD, ONE END OF SAID PUSH ROD BEING FREELY PIVOTED TO A LONGITUDINAL MIDPOINT OF SAID SLIDING BAR, A LEVER, 